The first round of nuclear talks in Vienna between Iran and the six world powers came to a close on Thursday morning. European Union foreign policy chief Catherine Ashton and Iranian Foreign Minister Mohammad Javad Zarif held a quick press conference soon after the talks were concluded, calling the discussions "a good start."

"We have had three very productive days during which we have identified all of the issues we need to address in reaching a comprehensive and final agreement," said Ashton. "There is a lot to do. It won't be easy but we have made a good start."

"In addition to our political discussions, we have started the technical work," she said. "And we have set a timetable of meetings initially over the next four months with a framework to continue our deliberations."

The sides agreed to hold a further round of talks in Vienna on March 17-20. The agreed-upon framework includes a schedule for follow-up meetings, and an agenda for issues to be discussed.

Zarif told reporters after the press conference with Ashton that the talks were "very serious and more positive than expected," adding that the two sides had consensus that only Iran's nuclear issue – and not its scientific and military capabilities, referring to subjects like its missile program – would on the agenda during these negotiations.

"We agreed that no one 'surprises' the other side with new claims," Zarif said.

The interim agreement gave the sides one year to finalize a comprehensive deal, Zarif said, but added that they were "trying to wrap up that in six months."

Ashton is planning to make an official visit to Iran on March 9-10, before the next round of talks. Austrian President Heinz Fischers said after meeting with Zarif that he too would make a trip to Iran, the first such visit by a Western state leader since the elections in the Islamic Republic.

U.S. official: We respect Netanyahu, but won't always agree

A senior U.S. official said following the talks that all sides feel that "some progress" has been made and that "we have a path for how the talks will proceed."

"There will not be a written agenda or framework - but we all know what it is and all issues will be on the table," said the official.

"This will be a complicated, difficult and lengthy progress but we aim to get the job done in six months," the official said, adding: "While we have much more work to do - we have come some distance in a relatively short time."

The U.S. official echoed his counterparts in calling the dialogue "substantive," and said that specific dates had been set for meetings over the next four months, with another month of negotiations left open on the calendar because "it will be more intense."

"Nothing will be agreed until everything is agreed," the U.S. official said.

The official said that an American delegation would travel to Israel and then to Saudi Arabia over the weekend to brief government officials in those two countries on the talks.

Answering a question about Prime Minister Benjamin Netanyahu's demand that any comprehensive agreement with Iran must include "zero enrichment and zero centrifuges," the U.S. official said: "We respect Netanyahu's statements and it is important to hear what our allies will have to say," adding: "But we are not always going agree."

As part of the negotiations, the sides have agreed to convene their political directors, alongside Ashton and Zarif, once a month over the course of the next four months. Between each meeting there will be intense meetings of expert working groups related pertaining to each issue individually – the future of uranium enrichments, the heavy water reactors in Arak, and lifting of sanctions.

One of the main issues to be determined is the question of whether to include Iran's ballistic missile program in list of topics to be discussed during the final-status negotiations. While the world powers demand the inclusion of the missile program, saying this falls under the implementation of UN Security Council resolutions, the Iranians insist on excluding the missile program as an area unrelated to the nuclear issue.

On Wednesday morning, an extended meeting was held between the Iranian delegation and representatives from the world powers – the U.S., Russia, China, Britain, France and Germany – followed by consultations by expert groups and separate meetings between the Iranians and different delegations. Several meetings also took place between Ashton, who manages the negotiations on behalf of the world powers, and Zarif.

Radio silence

Not unlike the first day of talks, Wednesday also saw radio silence maintained by both sides. In what seemed like a coordinated move, delegation representatives refused to divulge details on the content of the talks. The main messages communicated by the different diplomats, however, were positive nonetheless.

Deputy State Department spokesperson Marie Harf, who is also the spokesperson for the American delegation to the Vienna negotiations, called the talks "constructive" and said she believes progress has been made in recent days.

The Vienna talks had been supposed to last until Thursday evening, but the schedule has been changed in light of the escalation in Kiev. Ashton has called an emergency meeting of EU foreign ministers on Thursday afternoon to discuss the situation in the Ukraine. Therefore, it was decided to speed up the Vienna talks in order to bring them to a close on Thursday morning.

The head of the U.S. negotiating team, Wendy Sherman, will arrive in Israel on Friday brief her Israeli colleagues. Over the weekend, Sherman is expected to meet with Intelligence Minister Yuval Steinitz, National Security Adviser Yossi Cohen and with the head of the Foreign Ministry's strategic division, Jeremy Issacharoff.

A senior Israeli official said that even before the talks began, Steinitz spoke with Sherman and the French and British representatives in order to coordinate positions and stress the points Israel finds particularly imporant. Steinitz clarifies that Iran's missile program, and any other area addressed in Security Council resolutions, must be part of the agenda at the final-status talks.

One of the main points Steinitz underscored in conversations with Sherman and her British and French colleagues was the future of uranium enrichment on Iranian soil. Israel opposes any further uranium enrichment by Iran, while the world powers are willing to accept limited enrichment as part of a final-status agreement.

The interim agreement states that Iran will be able to continue uranium enrichment on its soil in a limited manner and "for practical needs." Steinitz told Sherman that the powers must stress to the Iranians that the term "practical needs" means "minimal enrichment."

Steinitz also expressed fear that using the excuse of "practical needs" for a civilian nuclear program, the Iranians could claim they need tens of thousands of centrifuges and will offer in return nothing more than heightened inspection of their nuclear facilities. In this way, Steinitz held, the Iranians will get international legitimacy to maintain their enrichment capabilities, and perhaps even enhance them.

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